The portal of the instant invention is a subcutaneous implantable access device that includes a reservoir and a septum through which fluid may be input or removed from the reservoir. Such subcutaneous implantable device is known and is commonly referred to as a port or portal, and is exemplified by the following patents assigned to the assignee as the instant application: U.S. Pat. Nos. 5,558,641, 5,562,618, 5,613,945, 5,743,873 and 5,989,216. The respective disclosures of the '641, '618, '945, '873 and '216 patents are incorporated by reference to the disclosure of the instant application. Such portals are implanted into patients, with the self resealable septums of the portals providing access to the reservoirs so that fluid medicaments and other infusate fluids may be stored in the reservoirs for infusion to the patients. Instead of storing medication to be infused to the patient, patient fluid such as blood may be withdrawn from the reservoir, by using for example a cannula or needle.
For portals that have been implanted into patients, oftentimes it is necessary to determine given properties or characteristics of those portals, for example determining whether a certain portal is adaptable to be used for power injection. Accordingly, it is desirable that some indicia be provided to a portal so that even after the portal has been implanted into a patient, the particular characteristic(s) or property(s) of the portal can be ascertained.
There are a number of implantable portals that have an identifier that is discernable by x-ray or palpations. These portals are disclosed in US patent publication Nos. 2009/0024024, 2007/0276344, 2005/0124980, 2006/0224129 and 2008/0319399. The portals disclosed in the noted patent publications either have septums that have protuberances formed at its outer surface so that the portals may be palpated by the user over the skin of the patient, or have identifiers etched to the body of the portals that are x-ray viewable.
In U.S. Pat. No. 8,092,435, assigned to the same assignee as the instant application, the inventors of the instant application disclose a septum with an identification indicia embedded onto the top of the elastomer structure with a clear coat of silicone covering the identification indicia. The main purpose of the '435 invention is to provide an indicia that identifies a characteristic of the portal. The indicia is formed by an impression at the top surface of a base that is filled with a radiographic material and covered with the silicone layer. The disclosure of the '435 patent is incorporated by reference to the disclosure of the instant application.